Question

I believe the solution to 2C-10 is wrong. The substitution according to the figure should be cosines rather than sines. Anyone disagrees?

Answer 1

I agree with you. Snell's law uses sines, but those of the angles formed by the ray and the normal line, which would be perpendicular to the beach in this example. For the angles shown in the diagram, we must use cosines. I notified the staff when I found the error several weeks ago, but it has not yet been corrected.

Answer 2

Cool. Thanks very much.